Color flat panel display

ABSTRACT

Disclosed is a color flat panel display comprising a rear glass, a rear electrode, a filament cathode for emitting electrons, a control electrode, a signal modulation electrode, a focus electrode, a horizontal deflection electrode, a vertical deflection electrode, a front glass on which a phosphor screen is formed, and a spacer for maintaining an interval between the electrodes, wherein the spacer is plate-shaped and has a space part through which electron beams pass at an inside of thereof.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a color flat panel display, andmore particularly, to a spacer forming the spacing between electrodes ofa color flat panel display.

[0003] 2. Description of the Related Art

[0004] Recently, an electroluminescent display (ELD), a plasma displaypanel (PDP), a liquid crystal display (LCD) and the like have beendeveloped as a color flat panel display. However, in comparison with acathode ray tube (CRT) that uses an electron beam, the conventionalcolor flat panel display bas not reached a satisfactory level in view ofperformances such as a luminance, a contrast and a color reproduction

[0005] To overcome the restrictions of the conventional color flat paneldisplay (the ELD, the PDP and the LCD) and implement a high-qualityimage comparable to the CRT, there have been proposed an improved colorflat panel display that is based on a screen scanning of an electronbeam.

[0006] Meanwhile, Japan Laid-open Publications No 3-184247 and No.3-205751 disclose an image display apparatus for displaying ahigh-quality image comparable to the CRT on a flat panel display thatuses an electron beam, in which an image displayed on a screen isdivided into unit cells constituting a matrix and then an electron beamis deflectively scanned to each unit cell, so that a phosphor screen islight-emitted to thereby display an entire color image.

[0007]FIG. 1 is a view of a conventional color flat panel display basedon a screen scanning of an electron beam.

[0008]FIG. 1 is an exploded perspective view showing main elements ofthe conventional color flat panel display. Referring to FIG. 1, theconventional color flat panel display includes a rear glass 1, a rearelectrode 2, a filament cathode 3, a control electrode 4, a signalmodulation electrode 5, a focus electrode 6, a horizontal deflectionelectrode 7, a vertical deflection electrode 8, and a front glass 9, allof which are arranged one after another. In addition, the rear glass 1and the front glass 9 are sealed to maintain a vacuum state.

[0009] In more detail, the rear electrode 2 is formed of a conductivematerial such as metal and graphite on a flat panel. The rear electrode2 is arranged in parallel with the filament cathode 3 and a negativevoltage is applied to the rear electrode 2 to thereby cause an electronemitted from the filament cathode 3 to be directed toward the screen.

[0010] Generally, the filament cathode 3 is formed coating an oxidecathode material on a surface of a tungsten wire. At this time, aplurality of filament cathodes are arranged to generate the electronbeam constantly distributed in a horizontal direction.

[0011] As an electrode for drawing the electron beam 11, the controlelectrode 4 is spaced apart from the filament cathode 3 by apredetermined distance and disposed in a direction of the screen. Also,the control electrode 4 is faced with the rear electrode 2 and formed ofa conductive plate in which passing holes are disposed at eachpredetermined distance in a horizontal direction and formed on ahorizontal line facing each filament cathode 3 by a predetermineddistance.

[0012] The signal modulation electrode 5 includes a row of conductiveplates, each of which is arranged on a position facing each passing holeof the control electrode 4 and spaced apart from the control electrode 4by a predetermined distance. At this time, each conductive plate is thinand long in a vertical direction. Each conductive plate of the signalmodulation electrode 5 has passing holes formed in the same plane on aposition facing each passing hole of the control electrode 4.

[0013] The focus electrode 6 is formed of a conductive plate havingpassing holes formed on each position facing each passing hole of thesignal modulation electrode 5. The horizontal deflection electrode 8includes two conductive plates meshed with each other on a sectionalportion and spaced apart by a predetermined distance on the same plane.

[0014] Further, the vertical deflection electrode 8 also includes twoconductive plates meshed with each other on a sectional portion andspaced apart by a predetermined distance on the same plane.

[0015] Generally, all of the above-described electrodes are manufacturedusing an Invar (Fe-Ni alloy) in order to prevent an image quality frombeing degraded due to a thermal deformation. Each of the controlelectrode 4, the signal modulation electrode 5, the focus electrode 6,the horizontal deflection electrode 7 and the vertical deflectionelectrode 8 is joined with an insulating adhesive.

[0016]FIG. 2 is a view explaining a phosphor screen of the conventionalcolor flat panel display.

[0017] Referring to FIG. 2, a phosphor screen 15 is formed on the frontglass 9 and R, G and B phosphors 12 are coated on an inner side of thefront glass 9. Black matrixes (BM) 14 are formed between the phosphors12.

[0018] In addition, a metal back 13 is formed on the phosphors 12 tothereby reflect and project a light generated by the phosphors 12 on thefront glass 9.

[0019] On the basis of the above structure, an operation of theconventional color flat panel display will be described below withreference to FIGS. 1 and 2.

[0020] If a voltage is applied to the filament cathode 3, electrons areemitted. At this time, the filament cathode 3 is heated by passing acurrent therethrough in order to easily obtain the electron emission.

[0021] The electrons emitted from the filament electrode 3 are dividedinto multiple parts by the passing holes of the control electrode 4 andits amount is controlled.

[0022] A passing amount of the electron beam 11 passed through thecontrol electrode 4 is controlled corresponding to an image signal atthe signal modulation electrode 5.

[0023] The electron beam 11 passed through the signal modulationelectrode 5 is focused at the passing holes of the focus electrode 6 dueto a static lens effect. The electron beam 11 is deflected by passingboth the horizontal deflection electrode 7 and the vertical deflectionelectrode 8 and then it is scanned to the phosphor 12 of correspondingunit cell 10, thereby displaying a desired image.

[0024] At this time, a voltage applied to the electrode adjacent to thescreen is maximally of 600 V and a voltage of the screen isapproximately of 10,000-14,000 V.

[0025] In other words, since a high voltage of approximately 10,000 v isapplied to the metal back 13, the electron beam 11 is accelerated to ahigh energy and collided against the metal back 13, therebylight-emitting the phosphor 12.

[0026]FIG. 3 is a view showing a structure of the vertical deflectionelectrode 8 in the conventional color flat panel display.

[0027] As shown in FIG. 3, the vertical deflection electrode 8 is madein a structure that two conductive plates 8 a and 8 b are meshed witheach other on a sectional portion and spaced apart by a predetermineddistance on the same plane.

[0028] In other words, it positive and negative voltages are applied tothe conductive plates 8 a and 8 b respectively, an electric field isgenerated, and the electric field causes the electric beam to bedeflected, thereby achieving a vertical deflection.

[0029] In addition, a horizontal deflection is achieved in thehorizontal deflection electrode 7 by the same principle as the verticaldeflection.

[0030]FIG. 4 is a view explaining an assembly process of the electrodes,in which a pre-sintering state and a post-sintering state are shown.

[0031] Explaining the assembly process of the electrodes with referenceto FIG. 4, crystalline glass rods 22 of a relatively low melting pointare inserted into both sides of amorphous glass rods 21 of a relativelyhigh melting point between the electrodes, and then the sinteringprocess is carried out. Consequently, the crystalline glass rods 22 aremelted to wrap the amorphous glass rods 21, thereby acting as anadhesive.

[0032] In other words, the amorphous glass rods 21 are made from crystalthat is the main raw material, and has a softening temperature ofapproximately 550° C. If the amorphous glass rods 21 are pressed atapproximately 450° C. while being sintered, the crystalline glass rods22 that have a melting point lower relative to the amorphous glass rods21 are melted, so that both electrodes are bonded.

[0033] At this time, a gap between both electrodes is maintained as muchas a diameter of the amorphous glass rod 21, and thus the amorphousglass rods 21 serve as the spacer.

[0034] In the meanwhile, in order to improve the brightness uniformityof an image that is the most important factor in reproducing a movingpicture, it is the most important to allow the gap between theelectrodes to be maintained at a constant size.

[0035] In particular, in case the gap between the electrodes in a colorflat panel display is changed, the image size of the electron beam ischanged too, so that the brightness uniformity is not obtained and awhole image quality is deteriorated.

[0036] Accordingly, it is necessary to maintain the gap between theelectrodes at a constant size. The amorphous glass rods 21 are made fromcrystal not having a variation in the shape or diameter at anapproximately 450° C. Then, since the cost of the amorphous glass rods21 corresponds to 70% of the overall cost of all the electrodes, themanufacturing costs of the color flat panel display increase.

[0037] In addition, it is requested to arrange the pair of crystallineglass rods 22 at both sides of the amorphous glass rods 21 during thebonding process of the respective electrodes. In order to bond all theelectrodes, working time and the number of the bonding process increase,so that there occurs a problem in that the manufacturing costs increase.

SUMMARY OF THE INVENTION

[0038] Accordingly, it is an object to simplify the manufacturingprocess and save the manufacturing costs by using an integral typespacer instead of using the amorphous glass rods and the crystallineglass rods so as to maintain the gap between the electrodes at aconstant size.

[0039] To achieve these objects and other advantages and in accordancewith the purpose of the invention, as embodied and broadly describedherein, there is provided a color flat panel display comprising a rearglass, a rear electrode, a filament cathode for emitting electrons, acontrol electrode, a signal modulation electrode, a focus electrode, ahorizontal deflection electrode, a vertical deflection electrode, afront glass on which a phosphor screen is formed, and a spacer formaintaining an interval between the electrodes, wherein the spacer isplate-shaped and has a space part through which electron beams pass atan inside of thereof.

[0040] In an aspect of the invention, there is provided a color flatpanel display comprising a rear glass, a rear electrode, a filamentcathode for emitting electrons, a control electrode, a signal modulationelectrode, a focus electrode, a horizontal deflection electrode, avertical deflection electrode, a front glass on which a phosphor screenis formed, and a spacer for maintaining an interval between theelectrodes, wherein the spacer is plate-shaped, has a space part throughwhich electron beams pass at an inside thereof, and is made ofceramic-based insulator.

[0041] In another aspect of the invention, there is provided a colorflat panel display comprising a rear glass, a rear electrode, a filamentcathode for emitting electrons, a control electrode, a signal modulationelectrode, a focus electrode, a horizontal deflection electrode, avertical deflection electrode, a front glass on which a phosphor screenis formed, and a spacer for maintaining an interval between theelectrodes, wherein the spacer is plate-shaped, has a space part throughwhich electron beams pass at an inside thereof, and comprises a metalmember and an insulator film coated on the metal member.

[0042] It is to be understood that both the foregoing generaldescription and the following detailed description of the presentinvention are exemplary and explanatory and are intended to providefurther explanation of the present invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings, which are included to provide afurther understanding of the present invention and are incorporated inand constitute a part of this application, illustrate embodiment(s) ofthe present invention and together with the description serve to explainthe principle of the present invention. In the drawings:

[0044]FIG. 1 is a view of a conventional color flat panel display basedon a screen scanning of an electron beam;

[0045]FIG. 2 is a view explaining the phosphor screen of theconventional color flat panel display;

[0046]FIG. 3 is a view showing a structure of the vertical deflectionelectrode of the conventional color flat panel display;

[0047]FIG. 4 is a view explaining an assembly process of the electrodes,in which a pre-sintering state and a post-sintering state are shown;

[0048]FIG. 5 is a view showing a structure of a color flat panel displayin accordance with an embodiment of the present invention;

[0049]FIG. 6 is a view showing a structure of a spacer in a color flatpanel display in accordance with the present invention;

[0050]FIG. 7 is a view showing another structure of the spacer in acolor panel display in accordance with the present invention;

[0051]FIG. 8 is a view showing a coupling structure of the spacer andthe signal modulation electrode in a color panel display in accordancewith the present invention;

[0052]FIG. 9 is a view showing a coupling process of the electrode andthe spacer in a color panel display in accordance with the presentinvention;

[0053]FIG. 10 is a view showing a structure of a spacer in accordancewith another embodiment of the present invention; and

[0054]FIG. 11 is a view showing another coupling process of theelectrodes and the spacer in a color panel display in accordance withthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0055] Reference will now be made in detail to a preferred embodiment ofthe present invention with reference to the attached drawings.

[0056]FIG. 5 is a view showing a structure of a color flat panel displayin accordance with an embodiment of the present invention.

[0057] Referring to FIG. 5, a color flat panel display of the presentinvention comprises a rear glass 1, a rear electrode 2, a filamentcathode 3 for emitting electrons, a control electrode 4, a signalmodulation electrode 5, a focus electrode 6, a horizontal deflectionelectrode 7, a vertical deflection electrode 8, a front glass 9 on whicha phosphor screen 15 is formed, and spacers 20 for maintaining aninterval between the electrodes. Each of the spacers 20 is plate-shaped,and has a space through which electron beams pass at an inside thereof.

[0058] The spacers 20 allow the electrodes to be spaced by a certaininterval from each other, and at the same time to be coupled with eachother. The space of each of the spacers 20 is varied in its shapedepending on the coupled electrode.

[0059] If a voltage is applied to the filament electrode 3, electronsare emitted. The filament electrode 3 is heated by flowing a currentsuch that electrons are emitted with ease.

[0060] In other words, proper voltages are respectively applied to therear electrode 2, the filament electrode 3 and the control electrode 4such that electrons are emitted from the surface of the filamentelectrode 3.

[0061] The electrons emitted from the filament electrode 3 are dividedinto a plurality of electron beams by passing holes of the controlelectrode 4, and the amount of the divided electron beam is alsocontrolled.

[0062] The amount of the electron beam 11 that passes through thecontrol electrode 4 is controllable at the signal modulation electrodeby image signals.

[0063] The electron beam 11 that has passed through the signalmodulation electrode 5 is focused at passing holes of the focuselectrode 6 by electrostatic lens effect, is deflected while passingthrough the horizontal deflection electrode 7 and the verticaldeflection electrode 8, and is scanned on the phosphor 12 within acorresponding unit cell 10, so that a desired image is displayed.

[0064]FIG. 6 is a view showing a structure of a spacer in a color flatpanel display in accordance with the present invention.

[0065] As shown in FIG. 6, the spacer 20 has a place shape, and includesa plurality of space portions through which electron beams pass at aninside thereof.

[0066] The shape of the plurality of space portions is changed dependingon the kind of the electrode coupled thereto. The spacer shown in FIG. 6is indicative of a spacer formed between the control electrode 4 and thesignal modulation electrode 5.

[0067] It is desirable that the spacer 20 is made of insulatingmaterial. The insulating material is preferably a ceramic-basedinsulating material.

[0068] Also, the insulating material is preferably aluminum oxide, morepreferably Al₂O₃.

[0069]FIG. 7 is a view showing another structure of the spacer in acolor panel display in accordance with the present invention.

[0070] As shown in FIG. 7, the spacer 20 includes a metal member 30 foreasy processing and an insulating film 31 coated on the metal member 30.

[0071] Considering the easy processing and the manufacturing costs, itis desirable that the metal member 30 is aluminum (Al).

[0072] Considering the insulation and processing properties, it isdesirable that the insulating film 31 is a ceramic-based insulatingmaterial.

[0073] Also, the insulating film 31 is preferably aluminum oxide, morepreferably Al₂O₃.

[0074]FIG. 8 is a view showing a coupling structure of the spacer andthe signal modulation electrode in a color panel display in accordancewith the present invention.

[0075] Referring to FIGS. 6 and 8, the space portions 32 of the spacer20 shown in FIG. 6 are formed to be matched with the electronbeam-passing holes respectively formed in the control electrode 4 andthe signal modulation electrode 5, and the signal modulation electrode 5is coupled to one surface of the spacer 20.

[0076] Although not shown in the drawings, the control electrode 4 iscoupled to the other surface of the spacer opposite to the one surfaceof the spacer 20 to which the signal modulation electrode 5 is coupled.

[0077] As aforementioned, the shape of the spacer portions 32 may bechanged depending on the shape of the electrodes coupled to bothsurfaces of the spacer 20.

[0078]FIG. 9 is a view showing a coupling process of the electrode andthe spacer in a color panel display in accordance with the presentinvention. In concrete, the coupling process of the control electrode 4and the signal modulation electrode 5 is well shown in FIG. 9.

[0079] First, frit glass layers 23 are coated on both surfaces of thespacer 20, and then the control electrode 4 and the signal modulationelectrode 5 are respectively positioned on the frit glass layers 23.

[0080] After that, the control electrode 4 and the signal modulationelectrode are sintered at a temperature range of 450-480° C. for 23-35minutes with being pressed, so that the frit glass layers 23 are meltedand coupled to.

[0081] Accordingly, a gap corresponding to the thickness of the spacer20 is formed between the control electrode 4 and the signal modulationelectrode 5.

[0082]FIG. 10 is a view showing a structure of a spacer in accordancewith another embodiment of the present invention, and FIG. 11 is a viewshowing another coupling process of the electrodes and the spacer in acolor panel display in accordance with the present invention.

[0083] The spacer 20 shown in FIG. 10 has a coupling hole 24, and thecontrol electrode 4 and the signal modulation electrode 5 also haveinsertion holes. Accordingly, the electrodes and the spacer 20 arealigned with each other such that the coupling hole is matched with theinsertion holes, and then they are unified by a bonding process.

[0084] The material used in the bonding process for unifying the spacer20 and the electrodes 4, 5 is preferably an insulating material.

[0085] As described previously, the color flat panel display of thepresent invention provides advantages to simplify the manufacturingprocess and save the manufacturing costs by using an integral typespacer instead of using the amorphous glass rods and the crystallineglass rods so as to maintain the gap between the electrodes at aconstant size.

[0086] The forgoing embodiment is merely exemplary and is not to beconstrued as limiting the present invention. The present teachings canbe readily applied to other types of apparatuses. The description of thepresent invention is intended to be illustrative, and not to limit thescope of the claims. Many alternatives, modifications, and variationswill be apparent to those skilled in the art.

What is claimed is:
 1. A color flat panel display comprising a rearglass, a rear electrode, a filament cathode for emitting electrons, acontrol electrode, a signal modulation electrode, a focus electrode, ahorizontal deflection electrode, a vertical deflection electrode, afront glass on which a phosphor screen is formed, and a spacer formaintaining an interval between the electrodes, wherein the spacer isplate-shaped and has a space part through which electron beams pass atan inside of thereof.
 2. The color flat panel display according to claim1, wherein the spacer is made of ceramic-based insulator.
 3. The colorflat panel display according to claim 1, wherein the spacer comprises ametal member and an insulator film coated on the metal member.
 4. Thecolor flat panel display according to claim 1, wherein the spacercomprises a metal member of aluminum (Al) and an insulating film ofAl₂O₃ coated on the metal member.
 5. The color flat panel displayaccording to claim 1, wherein the spacer includes coupling holescorresponding to the location and number of insertion holes formed ineach of the electrodes.
 6. A color flat panel display comprising a rearglass, a rear electrode, a filament cathode for emitting electrons, acontrol electrode, a signal modulation electrode, a focus electrode, ahorizontal deflection electrode, a vertical deflection electrode, afront glass on which a phosphor screen is formed, and a spacer formaintaining an interval between the electrodes, wherein the spacer isplate-shaped, has a space part through which electron beams pass at aninside thereof, and is made of ceramic-based insulator.
 7. The colorflat panel display according to claim 6, wherein the insulator film ismade of aluminum oxide.
 8. A color flat panel display comprising a rearglass, a rear electrode, a filament cathode for emitting electrons, acontrol electrode, a signal modulation electrode, a focus electrode, ahorizontal deflection electrode, a vertical deflection electrode, afront glass on which a phosphor screen is formed, and a spacer formaintaining an interval between the electrodes, wherein the spacer isplate-shaped, has a space part through which electron beams pass at aninside thereof, and includes a metal member and an insulator film coatedon the metal member.
 9. The color flat panel display according to claim8, wherein the insulator film is made of ceramic.
 10. The color flatpanel display according to claim 8, wherein the metal member is made ofaluminum (Al).
 11. The color flat panel display according to claim 8,wherein the insulator film is made of Al₂O₃.
 12. The color flat paneldisplay according to claim 8, wherein the insulator film is made ofaluminum oxide.
 13. The color flat panel display according to claim 8,wherein the spacer includes coupling holes corresponding to the locationand number of insertion holes formed in each of the electrodes.
 14. Acolor flat panel display comprising a rear glass, a rear electrode, afilament cathode for emitting electrons, a control electrode, a signalmodulation electrode, a focus electrode, a horizontal deflectionelectrode, a vertical deflection electrode, a front glass on which aphosphor screen is formed, and a spacer for maintaining an intervalbetween the electrodes, wherein the spacer is plate-shaped, has a spacepart through which electron beams pass at an inside thereof, andcomprises frit glasses coated and sintered on both surfaces of thespacer, the frit glasses being coupled with the electrodes.
 15. Thecolor flat panel display according to claim 14, wherein the spacer ismade of ceramic-based insulator.
 16. The color flat panel displayaccording to claim 14, wherein the spacer comprises a metal member andan insulator film coated on the metal member.
 17. The color flat paneldisplay according to claim 14, wherein the spacer comprises a metalmember of aluminum (Al) and an insulating film of Al₂O₃ coated on themetal member.